U.S. patent number 5,605,286 [Application Number 08/438,087] was granted by the patent office on 1997-02-25 for nozzle carrier of a windshield washing system for vehicles, particularly for vehicle headlights.
This patent grant is currently assigned to Hella KG Hueck & Co.. Invention is credited to Thomas Lind, Peter Orth, Martin Thorn.
United States Patent |
5,605,286 |
Orth , et al. |
February 25, 1997 |
Nozzle carrier of a windshield washing system for vehicles,
particularly for vehicle headlights
Abstract
A nozzle carrier for a windshield washing apparatus has an outer
cylinder (1) and a telescoping inner cylinder (2) in the outer
cylinder. The inner cylinder has at an end portion thereof a jet
nozzle (3) which can be shoved out of the outer cylinder. A first
plunger (4) is sealed about its periphery to the outer cylinder and
is movable by pressure of washing liquid away from a second plunger
(5). In this manner the inner cylinder is shoved out of the outer
cylinder. When both cylinders are at their greatest spacing from
one another they determine, together with the outer cylinder, a
space which serves to receive a particular quantity of washing
liquid. Thereafter, the second plunger is urged, by pressure of the
washing liquid, toward the first plunger. This causes, after the
opening of a valve in series with the jet nozzle, the washing
liquid to flow through a passageway (8) of the first plunger toward
the jet nozzle.
Inventors: |
Orth; Peter (Lippstadt,
DE), Lind; Thomas (Freudenberg, DE), Thorn;
Martin (Lippetal, DE) |
Assignee: |
Hella KG Hueck & Co.
(Lippstadt, DE)
|
Family
ID: |
6518072 |
Appl.
No.: |
08/438,087 |
Filed: |
May 8, 1995 |
Foreign Application Priority Data
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May 13, 1994 [DE] |
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44 16 924.8 |
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Current U.S.
Class: |
239/284.2;
239/570 |
Current CPC
Class: |
B60S
1/528 (20130101) |
Current International
Class: |
B60S
1/52 (20060101); B60S 1/46 (20060101); B05B
001/10 () |
Field of
Search: |
;239/88,92,570,322,284.2
;222/389,334 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0572147A1 |
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Dec 1993 |
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EP |
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2655531 |
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Jun 1978 |
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DE |
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3828999A1 |
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Mar 1990 |
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DE |
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9108956.5 |
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Sep 1991 |
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DE |
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4121316 |
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Jan 1992 |
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DE |
|
4143316A1 |
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Sep 1992 |
|
DE |
|
4338639A1 |
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Jun 1994 |
|
DE |
|
Primary Examiner: Weldon; Kevin
Attorney, Agent or Firm: Griffin, Butler, Whisenhunt &
Kurtossy
Claims
We claim:
1. Nozzle carrier of a windshield washing apparatus for vehicles,
particularly for vehicle headlights, having an outer cylinder (1),
a telescoping inner cylinder (2) in the outer cylinder with a jet
nozzle (3) at an end portion thereof which can be shoved from the
outer cylinder, first and second plungers (4, 5) for defining and
pressing toward the jet nozzle a particular quantity of washing
liquid, and a valve (6) coupled in series with the jet nozzle which
is opened in an outwardly-shoved position of the jet nozzle,
wherein:
the first plunger (4) is sealed about its periphery to the outer
cylinder, is movable by pressure of the washing liquid away from
the second plunger (5), and serves to push the jet nozzle of the
inner cylinder outwardly;
the first and second plungers, at their greatest spacing from one
another, determine, with the outer cylinder (2), a space which
serves to receive the particular quantity of washing liquid;
and
the second plunger (5) is movable by pressure of the washing liquid
toward the first plunger and, upon such moving, presses the
particular quantity of washing liquid through a passageway (8) of
the first plunger and out the jet nozzle.
2. Nozzle carrier as in claim 1 wherein is further included a
rod-like pull element (9) which: is fixedly connected to the second
plunger (5); which extends into the inner cylinder (2); and which
pulls the second plunger (5) with it when the jet nozzle is pushed
outwardly by engaging a first stop (10) of the inner cylinder (2),
wherein:
the pull element (9) passes through the passageway (8) of the first
plunger (4) and there is sufficient room for the passage of washing
liquid between it and walls defining the passageway (8) of the
first plunger (4).
3. Nozzle carrier as in claim 2 wherein a rear interior space (11)
of the nozzle carrier is defined when the jet nozzle is in a rest
position between a side of the first plunger (4) facing away from
the jet nozzle (3) and the outer cylinder (1) into which an opening
(12) of the outer cylinder (1) serves to supply washing liquid,
with the rear interior space (11), which receives the second
plunger (5), allowing liquid flow between both faces of the second
plunger (5).
4. Nozzle carrier as in claim 1 wherein the second plunger (5),
after the particular quantity of washing liquid has been sprayed
out, lies against the first plunger (4) and closes the passageway
(8) of the first plunger (4).
5. Nozzle carrier as in claim 1 wherein the valve (6) coupled in
series with the jet nozzle (3) is formed of a ring-shaped membrane
(13), which surrounds the passageway (8) on the side of the first
plunger (4) directed toward the jet nozzle (3) and which
peripherally seals the first plunger (4) to the inner cylinder (2),
and from two ring-shaped seal surfaces (15, 14) of the first
plunger (4) which lie opposite one another near a center of the
membrane (13).
6. Nozzle carrier as in claim 5 wherein the seal surface (14) of
the inner cylinder (2) is formed from a floor plate (16) of the
inner cylinder (2) in which a central hole (17) is made whose edge
area facing the jet nozzle is the first stop (10) for the rod-like
pull element (9), wherein the seal surface (14) of the floor plate
(16) surrounds the central hole (17) and at least one supply
opening (19) for the washing liquid is in the floor plate (16)
between the seal surface (14) and the floor plate's outer edge.
7. Nozzle carrier as in claim 6 wherein the floor plate (16) of the
inner cylinder (2) is a separate part, the membrane (13) is
sealingly seated between the floor plate (16) and an edge of the
inner cylinder (2), and a shell-shaped part (20) is mounted on the
floor plate (16) of the inner cylinder (2) to extend into the
interior of the inner cylinder (2), wherein the shell-shaped part
is sealed with the inner cylinder (2), with a free end portion of
the rod-like pull element (9) being movable into the shell-shaped
part (20) and the membrane (13) extending between the seal surface
(15) of the first plunger (4) and the inner cylinder (2).
8. Nozzle carrier as in claim 1 wherein a membrane (13) of elastic
material is formed on the first plunger (4).
9. Nozzle carrier as in claim 1 wherein the second plunger (5) is
held against a floor (29) of the outer cylinder (1) by a
self-releasing holding apparatus (18) when the jet nozzle (3) is in
a rest position.
10. Nozzle carrier as in claim 1 wherein the first plunger (4),
when the jet nozzle (3) is shoved out but before the valve (6) is
opened, contacts a second stop (22) of the outer cylinder (1) and
wherein the inner cylinder (2) lies against a third stop (23) of
the outer cylinder (1) after the valve (6) automatically opens.
Description
BACKGROUND OF THE INVENTION
This invention concerns a nozzle carrier of a windshield washing
apparatus for vehicles, particularly for vehicle headlights, having
an outer cylinder, a telescoping inner cylinder in the outer
cylinder with a jet nozzle at an end portion thereof which can be
shoved out of the outer cylinder, first and second plungers for
defining and pressing towards the jet nozzle a particular quantity
of washing liquid, and with a valve in series with the jet nozzle
which opens when the jet nozzle is in an outwardly-shoved
position.
Such a nozzle carrier for a windshield washing apparatus for
vehicles, particularly for vehicle headlights, is disclosed in
German Patent Publication DE 41 43 316. This windshield washing
apparatus has, exteriorly of outer and inner cylinders of the
nozzle carrier, a chamber which serves to store a particular
quantity of washing liquid. The particular quantity of washing
liquid can be pressed out of the chamber into the inner cylinder of
the nozzle carrier by compressed air. When this is done, the inner
cylinder is shoved from the outer cylinder to place a jet nozzle in
its operational position by pressure of the washing liquid. A valve
that is connected in series with the jet nozzle opens upon a
particular pressure of the washing liquid being executed. Only a
small amount of washing liquid can be stored in the inner cylinder.
Thus, in order to wash a windshield of a vehicle headlight a
washing procedure must be repeated many times. Further, in addition
to serving as a storage container for the washing liquid, the
external chamber for the particular quantity of washing liquid is
necessary because the particular quantity of washing liquid is
pressed into the nozzle carrier by compressed air. Further, in
addition to the valve which is in series with the jet nozzle, two
shoving valves and two check valves are necessary. A first plunger
is movably mounted in the inner cylinder and a second plunger is
movably mounted in the outer cylinder. The two plungers are
connected with one another by a rod-like pull element. The rod-like
pull element is tubularly shaped and thereby has a bore, or
passageway, for the washing liquid. After the external chamber is
filled with the particular quantity of washing liquid, compressed
air can, upon a shoving valve opening, enter the chamber and press
the washing liquid through the passageway of the pull element into
the inner cylinder. When this is done, the inner cylinder moves out
of the outer cylinder. After the particular quantity of the washing
liquid is pressed into the inner cylinder, the inner cylinder
carries the first plunger with it a short distance by impact. The
first plunger pulls with it, via the pull element, the second
plunger, which opens a shoving valve on its face directed away from
the jet nozzle. After the shoving valve is opened a check valve on
the first plunger closes the passageway of the pull element and the
compressed air presses against the face of the second plunger
directed away from the jet nozzle. Upon a particular pressure being
reached, an valve in series with the jet nozzle is opened and the
first and second plungers press, by means of being shoved toward
the jet nozzle, the washing liquid out of the jet nozzle. Upon
completion of this spraying process the inner cylinder impinges on
a contact which closes the shoving valve which is positioned
between a compressed air source and the chamber, Thereafter, the
second plunger is no longer engaged by compressed air and a spring
element positioned between the inner cylinder and the outer
cylinder shoves the inner cylinder into the outer cylinder and the
first and second plungers to their starting positions. During this
time a pump supplies washing liquid from a storage container into
the chamber and thereby opens a check valve of the chamber.
German Patent Publication DE 26 55 531 discloses a movable, or
shovable, washing apparatus for vehicles in which an external
cylinder arranged between a storage container for washing liquid
and a jet nozzle stores such a quantity of washing liquid that the
stored washing liquid is sufficient for an entire washing process.
The particular quantity of washing liquid is pressed by a plunger
to a jet nozzle, with the plunger being moved in the cylinder by
pressure of a following flow of washing liquid.
It is an object of this invention to provide a nozzle carrier of
the type described in the opening paragraph above for a windshield
washing apparatus for vehicles, particularly for vehicle
headlights, in which the particular quantity of washing liquid for
an entire washing procedure is sufficient and need not be
intermediately stored externally of a telescoping cylinder.
Further, pressure of the washing liquid should cause the inner
cylinder to be pressed out of the outer cylinder as well as the
particular quantity of washing liquid to be pressed out of the jet
nozzle.
SUMMARY OF THE INVENTION
According to principles of this invention, a nozzle carrier of a
windshield washing apparatus for vehicles, particularly for vehicle
headlights, has a first plunger which is sealed about its outer
periphery to an outer cylinder, is movable by pressure of washing
liquid away from a second plunger, and serves to push the jet
nozzle of the inner cylinder outwardly;
the first and second plungers, at their greatest spacing from one
another, define, with the outer cylinder, a space which serves to
receive the particular quantity of washing liquid;
the second plunger is movable, by pressure of the washing liquid,
toward the first plunger and, upon such moving, it presses the
particular quantity of washing liquid through a passageway out of
the jet nozzle.
BRIEF DESCRIPTION OF THE DRAWING
The invention is described and explained in more detail below using
the embodiments shown in the drawings. The described and drawn
features, in other embodiments of the invention, can be used
individually or in preferred combinations. The foregoing and other
objects, features and advantages of the invention will be apparent
from the following more particular description of a preferred
embodiment of the invention, as illustrated in the accompanying
drawings in which reference characters refer to the same parts
throughout the different views. The drawings are not necessarily to
scale, emphasis instead being placed upon illustrating principles
of the invention in a clear manner.
FIG. 1 is a middle, lengthwise, cross sectional view of a nozzle
carrier of this invention of a windshield washing apparatus for
vehicle headlights, with a jet nozzle thereof in a rest
position;
FIG. 2 is a view similar to FIG. 1 but with the jet nozzle at a
free end of an inner cylinder being shoved out of the outer
cylinder by pressure of washing liquid on the first plunger;
FIG. 3 is similar to FIGS. 1 and 2 but a valve on the first plunger
is opened;
FIG. 4 is a view similar to FIGS. 1-3 but a second plunger is
pressed toward the first plunger by means of pressure of the
washing liquid; and
FIG. 5 is an enlarged segmented view of a portion X of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A nozzle carrier of a windshield washing apparatus for vehicle
headlights can be mounted behind an opening of a vehicle body and
has a jet nozzle 3 which can be driven from a rest position of FIG.
1 through operational positions FIGS. 3 and 4. In the operational
position of FIG. 3 of the jet nozzle 3 a particular quantity of
washing liquid stored in the interior of the nozzle carrier is to
be sprayed onto a windshield of a vehicle headlight (not shown).
After the spraying procedure the jet nozzle 3 is to be returned to
its rest position. The nozzle carrier is coupled to a storage
container (not shown) for washing liquid and to a pump, by means of
which the washing liquid can be pressed into the interior of the
nozzle carrier and, by pressure created by the pump, can be sprayed
from the jet nozzle. When this is done the washing liquid is
atomized into small particles, which contact the windshield with a
sufficiently great speed that they, without the need of wiper vanes
even in very dirty cases, are cleaned.
The nozzle carrier has an outer cylinder 1 and an inner cylinder 2
which are constructed of resinous plastic. The outer cylinder 1 is
a combination of parts 24 and 25 which are snapped together in a
self attaching manner. Both parts 24 and 25 receive in their
interior a metal cylinder 26 which lies on an interior surface of
the outer cylinder 1 and extends across the junction of the two
parts 24, 25. The junction, or seam, between the two parts 24, 25
is sealed by a ring seal 27. A first plunger 4 is slidable in the
metal cylinder 26 with a peripheral teflon ring 28 sealing with the
interior surface of the metal cylinder 26. The metal cylinder 26 is
somewhat longer than the length of the throw, or travel, of the
first plunger 4. In the rest position of the jet nozzle 3 a rear
interior space 11 exists between the outer cylinder 1 and a floor
29 of the part 25 into which an opening 12 leads through a side
wall of the part 25. The opening 12 leads outwardly into a
passageway of a tube support 30 to which a hose (not shown) can be
sealingly attached to serve as a supply of washing liquid. A second
plunger 5 is arranged in the rear interior space 11 in the rest
position of the jet nozzle 3. The second plunger 5 is of an elastic
material and has a surrounding, or peripheral, sealing lip 31 which
is directed toward the floor 29 of the part 25. The rear interior
space 11, which is adjacent the metal cylinder 26, has a diameter
which, at least in places, is larger than the outer diameter of the
second plunger 5. Because the second plunger 5, in the rest
position of the jet nozzle 3, is spaced from the floor 29 of the
part 25, the rear interior space 11 communicates with both facings
of the second plunger 5. A free end of a rod-like pull element 9
engages in a centrally positioned opening of the second plunger 5
and is attached to the side of the second plunger 5 facing the
floor 29 by means of an attaching ring on the second plunger 5. The
opening 12, which serves as the supply for the washing liquid,
opens into the part 25 between the second plunger 5 and the metal
cylinder 26 and the first plunger 4 in the interior space 11 of the
outer cylinder 1. In the rest position of the jet nozzle 3 the
second plunger 5 is attached to the floor 29 of the part 25 by
means of a self-releasing holding apparatus 18.
The first plunger 4, which is surrounded by the teflon ring 28, is
formed, together with a ring-shaped membrane 13 which surrounds a
passageway 8 of the first plunger 4, from one piece of elastic
material, such as rubber. In the rest position of the jet nozzle 3
a surrounding edge defining the passageway 8 of the first plunger 4
engages a spherically-shaped sealing surface 33 of a free end
portion of the rod-like pull element 9 which is attached in the
central opening of the second plunger 5. The center point of the
spherically-shaped sealing surface 33 lies at a central length axis
of the nozzle carrier. The ring-shaped membrane 13 is formed about
a free edge of a collar 34 surrounding the passageway 8 of the
first plunger on a side of the first plunger 4 facing away from the
second plunger 5. The inner cylinder 2, which is telescopingly
movable in the outer cylinder 1 and which supports the jet nozzle 3
at its free end, is shoved onto a surrounding edge portion of the
ring-shaped membrane 13 at a funnel-like end portion thereof. The
ring-shaped membrane 13 has at a free edge a peripheral packing, or
enlargement, 36 which grips into a floor plate 16 in an end portion
35 of the inner cylinder 2. The floor plate 16 is inset in a self
attaching manner in the funnel-shaped end portion 35 of the inner
cylinder 2 and has a shell-shaped part 20 in the inner cylinder 2
which is sealingly closed at its free end by a stopper 37. A
centrally positioned hole 17 is in the floor plate 16 which leads
to the interior of the shell-shaped part 20. The rod-like pull
element 9 engages with play an edge forming the hole 17, with a
self-guiding catch 38 engaging behind an edge area defining the
hole 17 directed toward the jet nozzle, and upon movement of the
second plunger 5 the rod-like pull element 9 can be driven into the
interior of the shell-shaped part 20. A ring-shaped seal surface 14
of the floor plate 16 extends about the hole 17 against which, in
the rest position of the jet nozzle 3, the collar 34 lies so as to
serve as a sealing surface 15. Supply openings 19 are in the floor
plate 16 between the ring-shaped seal surface 14 and the free edge
of the ring-shaped membrane 13 which supply openings lead to a
space between the shell-shaped part 20 and the inner cylinder 2.
The first plunger 4, in an operational position of the jet nozzle
3, lies at a second stop 22 of the part 24 of the outer cylinder 1.
The second stop 22 is formed from a surrounding shoulder on the
inner surface of the part 24. Between the second stop 22 and the
free end of the outer cylinder 1 adjacent to the jet nozzle 3, the
outer cylinder 1 has a smaller internal diameter than at the part
in which the first plunger is movable. The funnel-shaped part 35 of
the inner cylinder 2 is movable in the part of the outer cylinder 1
adjacent the metal cylinder 26. In this regard, much play is
created between the outer edge of the funnel-shaped end portion 35
of the inner cylinder 2 and the interior of the part 24 of the
outer cylinder 1. A spring element 39 is placed between an outer
edge of the funnel-shaped end portion 35 and an inner edge of the
part 24 adjacent the jet nozzle 3. The spring element 39 is a coil
spring which is shoved onto the inner cylinder 2 and which presses
the inner cylinder 2, together with the first and second plungers
4, 5, toward the floor 29 of the part 25.
When washing liquid is pressed between the two plungers 4, 5 the
second plunger 5, at first, stays in its rest position while the
first plunger 4, because of pressure of the washing liquid against
the force of the spring element 39, is shoved away from the second
plunger 5. The second plunger 5 is pulled with the first plunger 4
when the catch 38 of the rod-like pull element 9 lies against the
first stop 10 of the floor plate 16. This pulling procedure ends
when the first plunger 4 contacts the second stop 22 of the outer
cylinder 1. When the pulling procedure of the second plunger 5
begins, the second plunger 5 releases itself from the holding
apparatus 18 holds it to the floor 29. When the pull procedure
ends, the sealing lip 31 of the second plunger 5 sealingly engages
on the inner side of the metal cylinder 26. Until this point, both
seal surfaces 14, 15 of the valve 6 sealingly oppose, or engage,
one another. Only after the facing side of the second plunger 5
directed toward the floor 29 is acted on by pressure of the washing
liquid and the first plunger 4 contacts the second stop 22 of the
outer cylinder 1 does the valve 6 open. That is, the membrane 13,
which is constructed of an elastic material, allows a lifting of
the floor plate 16 from the seal surface 15 of the first plunger 4.
So that the membrane 13 is not overloaded with tension, it is
beneficial for the inner cylinder 2 to contact a third stop 23 of
the outer cylinder 1. The jet nozzle 3 is then in a fully
operational position. Because the valve 6 is now open, the second
plunger 5 can move further toward the first plunger 4. In this
manner, the second plunger 5 presses the particular quantity of
washing liquid enclosed between it and the first plunger 4 through
the passageway 8 of the first plunger 4, through the open valve 6,
and through the supply opening 19 of the inner cylinder 2 toward
the jet nozzle 3. After the particular quantity of washing liquid
has been sprayed out, which is sufficient washing liquid for an
entire wash procedure of a windshield, the spherical-shaped sealing
surface 33 of the second plunger 5 lies firmly against the first
plunger 4. Thus, no further washing liquid can exit from the jet
nozzle 3, even if the pump continues to operate. After the pump has
automatically turned off, the spring element 39 urges the inner
cylinder 2, together with the first and second plungers 4 and 5,
toward the floor 29 of the outer cylinder 1 until the jet nozzle 3
reaches its rest position. For a single jet nozzle the volume for
the particular quantity of washing liquid can be varied as desired
by a change in length of the rod-like pull element 9.
The construction of the valve 6 and the first and second plungers 4
and 5 are shown in detail in FIG. 5. The first plunger 4, which is
constructed of an elastic material with the ring-shape membrane 13,
is stiffened by a metal ring 21 formed therein. The collar 34,
whose seal surface 15 lies opposing the seal surface 14 of the
floor plate 16, is also stiffened by the metal ring 21. The seal
surface 15 of the collar 34 forms a part of a sphere whose center
lies on the length axis of the nozzle carrier while the seal
surface 14 is a peripheral edge of the floor plate 16. The metal
ring 21 has an outwardly-directed edge portion 40 with which the
first plunger contacts the second stop 22 of the outer cylinder 1.
The free edge portion of the funnel-shaped end portion 35 of the
inner cylinder 2 serves as a support element for the membrane 13.
Thus, this also, upon a very large pressure of the washing liquid,
cannot stretch so far inwardly that it rubs against the inner
surface of the outer cylinder 1 to be thereby damaged. The holding
apparatus 18, between the second plunger 5 and the floor 29 of the
outer cylinder 1, is comprised of a hollow projection of the floor
29 which grips into a depression of the second plunger 5.
With a beneficial embodiment of this invention the space which
serves to store the particular quantity of washing liquid does not
depend on the length nor diameter of the inner cylinder. Thus, the
inner cylinder need not have larger dimensions than is necessary.
The outer cylinder, in which the particular quantity of washing
liquid can be stored, is in the vehicle covered by the vehicle body
and can be formed to be as large as is necessary.
In a nozzle carrier with a rod-shaped pull element which is fixedly
coupled to the second plunger and movable in the inner cylinder,
and which, upon the jet nozzle being shoved out, by its contact
with a first stop on the inner cylinder, pulls the second plunger
with it, it is further beneficial that the pull element passes
through the passageway of the first plunger and that there is
sufficient room created between it and the passageway of the first
plunger for supplying the washing liquid. In this regard, the path
along which the second plunger is pulled should be so long that the
first and second plungers, together with the outer cylinder,
sealingly enclose the particular quantity of washing liquid between
them. Thereafter, the following washing liquid presses exclusively
against the second plunger which shoves the first plunger via the
sealingly enclosed particular quantity of washing liquid toward the
jet nozzle until the first plunger contacts the stop on the outer
cylinder. Thereafter pressure against the valve in series with the
jet nozzle is increased to open it. The particular quantity of
washing liquid is pressed through the valve to the jet nozzle and
sprayed out of it. After the particular quantity of washing liquid
is sprayed out, the inner cylinder, which carries the jet nozzle,
and the first and second plungers can be shoved to their rest
positions by means of a spring element mounted in the nozzle
carrier.
In this connection, it is further beneficial that, when the jet
nozzle is in its rest position, between the side of the first
plunger directed away from the jet nozzle and the outer cylinder a
rear interior space of the nozzle carrier is created into which an
opening of the outer cylinder extends serving as a supply for the
washing liquid, with the rear interior space for receiving the
plunger communicating with both facing sides of the second plunger
and the opening for supplying the washing liquid being arranged in
the outer cylinder between both plungers. In this manner, no
additional valve is needed to move the nozzle carrier. Both facing
sides of the second plunger are, in the rest position of the second
plunger, contacted by following, flowing, washing liquid until it,
the second plunger, is pulled by the first plunger. When this takes
place, it is practical that the rear interior space of the outer
cylinder, which in the rest position of the jet nozzle receives the
second plunger, at least in the area of the second plunger, has a
larger interior diameter than the outer diameters of the first and
second plungers.
Further, it is beneficial that the second plunger lies against the
first plunger after the particular quantity of washing liquid has
been sprayed out and closes the passageway of the first plunger. In
this manner no further washing liquid can exit from the jet nozzle
after the particular quantity of washing liquid has exited.
It is further beneficial that the valve connected upstream of and
in series with the jet nozzle is formed of the ring-shaped membrane
which surrounds the passageway on the side of the first plunger
facing the jet nozzle to surroundingly seal the first plunger with
the inner cylinder and of two opposite ring-shaped seal surfaces,
respectively of the first plunger and the inner cylinder, with the
membrane between them. In this manner the valve which is in series
with the jet nozzle can be opened only after the first plunger
contacts the stop of the outer cylinder. It is thereby assured
that, even with pressure fluctuations, premature exiting of washing
liquid from the jet nozzle is prevented. In this regard, it is also
practical that, in the operational position of the jet nozzle, the
inner cylinder contacts a stop of the outer cylinder. Thus, the
valve, which is constructed from the membrane, is not overloaded in
tension when it is opened and the operational life of the membrane
is increased.
It is additionally beneficial that the seal surface of the inner
cylinder is formed by the floor plate of the inner cylinder in
which a central hole is defined by an edge which serves as a first
stop directed toward the jet nozzle for the rod-like pull element,
with the seal surface of the floor plate surrounding the central
hole, and there being at least one supply opening for the washing
liquid in the floor plate between the seal surface and the floor
plate's outer edge. Such an embodiment is uncomplicated and cost
effective to manufacture. In this regard, it is further practical
that the floor plate of the inner cylinder is a separate part, that
the membrane is sealingly seated between it and the edge of the
inner cylinder, and that the shell-shaped part is mounted on the
floor plate of the inner cylinder to extend into the interior of
the inner cylinder and is formed to be sealed toward the inner
cylinder, whereby the free end portion of the rod-like pull element
can extend into the shell-shape part and the membrane extends
between the seal surfaces of the first plunger and the inner
cylinder. In this manner the particular quantity of washing liquid
can only flow into the interior of the inner cylinder when the
valve is opened. So that the function of the nozzle carrier is
assured, the interior of the shell-shape part must be hydraulically
coupled to the passageway for the washing liquid via the central
opening of the floor plate.
Further, it is beneficial that the first plunger and the membrane
are molded as one piece of elastic material. The membrane has a
sufficient elasticity while the plunger is sufficiently stiff if
the plunger, of elastic material, includes an encircling metal
ring. A sealing coupling between the membrane and the plunger is
certain.
Further, it is beneficial that, in the rest position of the jet
nozzle, the second plunger is held at a floor of the outer cylinder
by a self releasing holding apparatus. In this manner, the second
plunger cannot be prematurely moved by pressure of the washing
liquid, but rather is only moved when the second plunger is pulled
by the first plunger. The holding apparatus is self activating.
The embodiments of the invention in which an exclusive property or
privilege are claimed are defined as follows:
* * * * *